사람 구강암세포 KB에서 microRNA 발현 분석

Abstract

MicroRNAs (miRNAs) are form of small noncoding RNAs that regulate the expression of genes either by inhibiting mRNA translation or by inducing its degradation. Small microRNAs play important roles in regulating a large number of cellular processes, including development, proliferation and apoptosis. Moreover, miRNAs function as oncogenes or tumor suppressors to modulate multiple oncogenic cellular processes in cancer development, cell proliferation, apoptosis, invasion and metastasis of human cancers. In this study, the expression profiles of miRNAs were compared and analyzed for establishment of miRNAs related cancer cell growth inhibition in normal human oral keratinocytes (NHOK) and KB human oral cancer cells. To determine the expression profiles of miRNAs in NHOK and KB cells, it was examined by miRNA microarray analysis, quantitative real-time PCR analysis (qRT-PCR), MTT assay and gene array analysis. In miRNA microarray analysis, 164 miRNAs and 149 miRNAs were found up- and down-regulated in KB cells compared to NHOK among the 1,769 miRNAs examined, respectively. miR-30a, miR-99a and miR-155 were up-regulated in KB cells compared to NHOK more than 10 times, in contrast miR-205, miR-203 and miR-200c were down-regulated more than 10 times. In qRT-PCR analysis, the expression levels of miR-30a, miR-99a and miR-155 were increased in KB cells compared to NHOK more than 15 times, and miR-205, miR-203 and miR-200c were decreased more than 10 times. Importantly, the overexpression of miR-205 and miR-203 significantly inhibited the growth of KB cells. In gene array analysis, 3,154 genes and 2,709 genes were found up- and down-regulated more than 2 times in the miR-205 overexpressed-KB cells compared to control KB cells, respectively. The overexpressed miR-203 in KB cells induced the increase of 2,707 gene expressions and decrease of 2,352 gene expressions. These results show that the miR-205 and miR-203 decrease in KB cells compared to NHOK, and inhibit proliferation of KB human oral cancer cells. Moreover, these in vitro results indicate miR-205 and miR-203 have significant therapeutic potential as the molecular medicine for the treatment of oral cancer by turning on silenced tumor suppressor genes by targeting with miRNA.